Polymeric polymerization initiator and method for producing polymeric polymerization initiator

ABSTRACT

A polymeric polymerization initiator represented by the following formula (I). M 1   a M 2   b D 1   c D 2   d T 1   e T 2   f Q g  (I) M 1 =R 1   3 SiO 1/2  M 2 =R 1   2 R 2 SiO 1/2  D 1 =R 1   2 SiO 2/2  D 2 =R 1 R 2 SiO 2/2  T 1 =R 1 SiO 3/2  T 2 =R 2 SiO 3/2  Q=SiO 4/2  [R 1  represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R 2  represents a group having a ketene silyl acetal structure represented by the following formula (II). (A represents a single bond or a divalent organic group, R 3  represents a hydrogen atom or a substituted or unsubstituted alkyl group, and R 4  represents a substituted or unsubstituted alkyl group.) “a”, “b”, “c”, “d”, “e”, “f”, and “g” represent 0 or a positive integer where b+d+f≥1. An order of bonding of siloxane units is optionally determined.]

TECHNICAL FIELD

The present invention relates to: a novel polymeric polymerizationinitiator; and a method for producing the polymeric polymerizationinitiator.

BACKGROUND ART

A (meth)acrylic-grafted silicone having a silicone chain on a main chainand having a (meth)acryl (the term “(meth)acryl” used in the followingdescription refers to methacryl and acryl) chain on a side chain hasboth a hydrophobic moiety and a polar moiety, and therefore, functionsas a surfactant, and is used as a powder processing agent or a materialfor cosmetics. Patent Documents 1 and 2 disclose methods for producingthis (meth)acrylic-grafted silicone.

Examples of the polymerization initiator in the method for producing a(meth)acrylic-grafted silicone of Patent Document 1 include radicalpolymerization initiators such as an azo initiator, a peroxideinitiator, a persulfuric initiator, and a photopolymerization initiator.Examples of the polymerization initiators used in Patent Document 2include radical polymerization initiators, specifically, a thermalpolymerization initiator and a photopolymerization initiator.

Generally, a (meth)acrylic-grafted silicone is synthesized by a radicalgenerated by an ordinary radical polymerization initiator such as thosedisclosed in Patent Document 1 and Patent Document 2 being transferredonto a sulfur atom of a mercapto-modified silicone by a chain transferreaction, and (meth)acrylic monomers being polymerized therefrom.However, when a (meth)acrylic-grafted silicone is synthesized by such amethod, the ordinary radical initiator, being the source of the radical,also becomes a polymerization initiation site, and (meth)acrylicmonomers become polymerized. Consequently, there has been a problem thatthe final product becomes a mixture of a (meth)acrylic-grafted siliconeand a (meth)acrylic polymer.

Meanwhile, a polymeric polymerization initiator is a polymer having afunctional group that may become a polymerization initiation site, andcharacteristic polymers such as a graft copolymer or a block copolymercan be polymerized by polymerizing monomers using the polymericpolymerization initiator. In addition, theoretically, it is possible tosuppress the product from becoming a mixture of a (meth)acrylic-graftedsilicone and a (meth)acrylic polymer as described above sincepolymerization initiation sites are only present on the polymer chain.

However, a polymeric polymerization initiator for synthesizing a(meth)acrylic-grafted silicone has not been considered sufficiently. Inparticular, consideration of a polymeric polymerization initiator whichenables a (meth)acrylic-grafted silicone to be synthesized by grouptransfer polymerization has been insufficient.

In addition, Patent Document 3 discloses a silicone having a ketenesilyl acetal structure as an intermediate for synthesizing asulfonyl-modified silicone. However, the silicone is not used as apolymeric polymerization initiator.

CITATION LIST Patent Literature

Patent Document 1: JP 2014-177447 A

Patent Document 2: JP 2008-274116 A

Patent Document 3: U.S. Pat. No. 5,326,890 B2

SUMMARY OF INVENTION Technical Problem

The present invention has been made in view of the above-describedcircumstances, and an object thereof is to provide: a polymericpolymerization initiator for obtaining a (meth)acrylic-grafted siliconeby group transfer polymerization; and a method for producing thepolymeric polymerization initiator.

Solution to Problem

To solve the above-described problems, the present invention provides

a polymeric polymerization initiator represented by the followinggeneral formula (I):M¹ _(a)M² _(b)D¹ _(c)D² _(d)T¹ _(e)T² _(f)Q_(g)  (I)M¹=R¹ ₃SiO_(1/2)M²=R¹ ₂R²SiO_(1/2)D¹=R¹ ₂SiO_(2/2)D²=R¹R²SiO_(2/2)T¹=R¹SiO_(3/2)T²=R²SiO_(3/2)Q=SiO_(4/2)

wherein in the general formula (I), R¹ each independently represents ahydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10carbon atoms, or a substituted or unsubstituted aryl group having 6 to22 carbon atoms; R² represents a group having a ketene silyl acetalstructure represented by the following general formula (II):

wherein in the general formula (II), A represents a single bond or adivalent organic group, R³ each independently represents a hydrogen atomor a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, and R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms,

“a”, “b”, “c”, “d”, “e”, “f”, and “g” represent 0 or a positive integerwhere b+d+f≥1, and the polymerization initiator represented by thegeneral formula (I) has a number-average molecular weight of 1,000 to1,000,000 g/mol; and an order of bonding of siloxane units representedby M¹, M², D¹, D², T¹, T², and Q is optionally determined.

The inventive polymeric polymerization initiator as described makes itpossible to synthesize a (meth)acrylic-grafted silicone by grouptransfer polymerization without the presence of a (meth)acrylic polymerderived from an ordinary radical initiator.

Furthermore, the present invention provides a method for producing theabove-described polymeric polymerization initiator, comprising a step ofadding a compound represented by the following general formula (III) toa hydrogensiloxane represented by the following general formula (IV) bya hydrosilylation reaction,

wherein in the general formula (III), A represents a single bond or adivalent organic group, R³ each independently represents a hydrogen atomor a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, and R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms,M³ _(h)D³ _(i)T³ _(j)Q_(k)  (IV)M³=R⁵ ₃SiO_(1/2)D³=R⁵ ₂SiO_(2/2)T³=R⁵SiO_(3/2)Q=SiO_(4/2)

wherein R⁵ each independently represents a hydrogen atom, a substitutedor unsubstituted alkyl group having 1 to 10 carbon atoms, or asubstituted or unsubstituted aryl group having 6 to 22 carbon atoms, andat least one is a hydrogen atom; “h”, “i”, “j”, and “k” represent 0 or apositive integer where h+i+j≥1, and the hydrogensiloxane represented bythe general formula (IV) has a number-average molecular weight of 500 to900,000 g/mol; and an order of bonding of siloxane units represented byM³, D³, T³, and Q is optionally determined.

The inventive polymeric polymerization initiator can be produced by suchan addition reaction.

Advantageous Effects of Invention

By using the inventive polymeric polymerization initiator, it ispossible to synthesize a (meth)acrylic-grafted silicone by grouptransfer polymerization without the presence of a (meth)acrylic polymerderived from an ordinary radical initiator.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a general view of a ¹H NMR chart after the reaction between ahydrogensiloxane and a compound represented by the formula (1) inExample 1.

DESCRIPTION OF EMBODIMENTS

The present inventor has repeated ingenuity, and as a result, has foundthat a silicone having a ketene silyl acetal structure represented bythe following general formula (I) can be suitably used as a polymericpolymerization initiator that can synthesize a (meth)acrylic-graftedsilicone by group transfer polymerization, and completed the presentinvention.

That is, the present invention is a polymeric polymerization initiatorrepresented by the following general formula (I):M¹ _(a)M² _(b)D¹ _(c)D² _(d)T¹ _(e)T² _(f)Q_(g)  (I)M¹=R¹ ₃SiO_(1/2)M²=R¹ ₂R²SiO_(1/2)D¹=R¹ ₂SiO_(2/2)D²=R¹R²SiO_(2/2)T¹=R¹SiO_(3/2)T²=R²SiO_(3/2)Q=SiO_(4/2)

wherein in the general formula (I), R¹ each independently represents ahydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10carbon atoms, or a substituted or unsubstituted aryl group having 6 to22 carbon atoms; R² represents a group having a ketene silyl acetalstructure represented by the following general formula (II):

wherein in the general formula (II), A represents a single bond or adivalent organic group, R³ each independently represents a hydrogen atomor a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, and R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms,

“a”, “b”, “c”, “d”, “e”, “f”, and “g” represent 0 or a positive integerwhere b+d+f≥1, and the polymerization initiator represented by thegeneral formula (I) has a number-average molecular weight of 1,000 to1,000,000 g/mol; and an order of bonding of siloxane units representedby M², M², D², D², T¹, T², and Q is optionally determined.

The inventive polymeric polymerization initiator is represented by thegeneral formula (I), and R² has a ketene silyl acetal structure. Sincethe ketene silyl acetal structure functions as an initiator of grouptransfer polymerization, the inventive polymeric polymerizationinitiator can be used as a polymeric polymerization initiator of grouptransfer polymerization.

In the general formula (I), R² each independently represents a hydrogenatom, a substituted or unsubstituted alkyl group having 1 to 10 carbonatoms, or a substituted or unsubstituted aryl group having 6 to 22carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms or anaryl group having 6 to 14 carbon atoms, further preferably a methylgroup or a phenyl group. R² represents a group having a ketene silylacetal structure represented by the general formula (II).

In the general formula (I), the order of bonding of the repeating unitsrepresented by M¹, M², D¹, D², T¹, T², and Q is optionally determined,and an arrangement constituted by the respective repeating units may beirregular, or may be regular. “a”, “b”, “c”, “d”, “e”, “f”, and “g”represent 0 or a positive integer, and the polymerization initiatorrepresented by the general formula (I) has a number-average molecularweight of 1,000 to 1,000,000 g/mol, further preferably a number-averagemolecular weight of 1,000 to 100,000 g/mol, and further preferably anumber-average molecular weight of 2,000 to 20,000 g/mol. b+d+f≥1,preferably 1 to 5000, further preferably 1 to 500. Note that in thepresent invention, the number-average molecular weight is a value interms of polystyrene in GPC (gel permeation chromatography) analysis(hereinafter, number-average molecular weight refers to such a value interms of polystyrene). If “b”, “d”, and “f” do not satisfy theconditional expression, the polymeric polymerization initiator of thegeneral formula (I) does not have R² in a molecule thereof, and does notpolymerize. In addition, if the number-average molecular weight of thepolymeric polymerization initiator is outside the above-described range,reactivity of the polymerization becomes poor.

In the general formula (II), A represents a single bond or a divalentorganic group, preferably an alkylene group having 1 to 10 carbon atomsor a substituted or unsubstituted divalent hydrocarbon group having 1 to20 carbon atoms optionally containing one or more selected from —O—,—S—, and NR— (R represents a monovalent hydrocarbon group having 1 to 20carbon atoms) (note that oxygen atoms, sulfur atoms, and nitrogen atomsare not adjacent to one another), further preferably an alkylene grouphaving 0 to 6 carbon atoms. R³ each independently represents a hydrogenatom or a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, preferably an alkyl group having 1 to 3, and further preferably amethyl group. R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms, preferably analkyl group having 1 or 2 carbon atoms, and further preferably a methylgroup.

The inventive polymeric polymerization initiator can be obtained byadding a compound represented by the following general formula (III) toa hydrogensiloxane represented by the following general formula (IV) bya hydrosilylation reaction.

Hereinafter, a method for producing the inventive polymericpolymerization initiator will be described in detail. This productionmethod includes a step of obtaining the polymeric polymerizationinitiator by adding a compound represented by the following generalformula (III):

to a hydrogensiloxane represented by the following general formula (IV)by a hydrosilylation reaction.M³ _(h)D³ _(i)T³ _(j)Q_(k)  (IV)M³=R⁵ ₃SiO_(1/2)D³=R⁵ ₂SiO_(2/2)T³=R⁵SiO_(3/2)Q=SiO_(4/2)(R⁵ each independently represents a hydrogen atom, a substituted orunsubstituted alkyl group having 1 to 10 carbon atoms, or a substitutedor unsubstituted aryl group having 6 to 22 carbon atoms, and at leastone is a hydrogen atom. “h”, “i”, “j”, and “k” represent 0 or a positiveinteger where h+i+j≥1, and the hydrogensiloxane represented by thegeneral formula (IV) has a number-average molecular weight of 500 to900,000 g/mol. The order of bonding of siloxane units represented by M³,D³, T³, and Q is optionally determined.)

In the general formula (III), A, as described above, represents a singlebond or a divalent organic group, preferably an alkylene group having 0to 10 carbon atoms or a substituted or unsubstituted divalenthydrocarbon group having 1 to 20 carbon atoms optionally containing oneor more selected from —O—, —S—, and NR—(R represents a monovalenthydrocarbon group having 1 to 20 carbon atoms) (note that oxygen atoms,sulfur atoms, and nitrogen atoms are not adjacent to one another),further preferably an alkylene group having 0 to 6 carbon atoms. R³ eachindependently represents a hydrogen atom or a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms, preferably analkyl group having 1 to 3, further preferably a methyl group. R⁴ eachindependently represents a substituted or unsubstituted alkyl grouphaving 1 to 4 carbon atoms, preferably an alkyl group having 1 to 2carbon atoms, further preferably a methyl group.

Examples of the compound represented by the general formula (III)include compounds having the following structures, but are not limitedthereto.

In the general formula (IV), R⁵ each independently represents a hydrogenatom, a substituted or unsubstituted alkyl group having 1 to 10 carbonatoms, or a substituted or unsubstituted aryl group having 6 to 22carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms.However, at least one is a hydrogen atom. “h”, “i”, “j”, and “k”represent 0 or a positive integer, and the hydrogensiloxane representedby the general formula (IV) has a number-average molecular weight of 500to 900,000 g/mol, further preferably 1,000 to 100,000 g/mol, andparticularly preferably 2,000 to 20,000 g/mol. If every R⁵ is not ahydrogen atom, the produced compound cannot be polymerized. In addition,if the number-average molecular weight of the hydrogensiloxane of thegeneral formula (IV) is outside the above-described range, reactivity ofthe produced polymeric polymerization initiator becomes poor.

The addition reaction is preferably performed with a catalyst, and aknown addition reaction catalyst can be used. Examples include metalcatalysts containing platinum, palladium, rhodium, ruthenium, gold,nickel, or the like. In particular, a catalyst containing platinum,palladium, or rhodium is preferable. A catalyst containing platinum isfurther preferable, and more specifically, PtCl₄, H₂PtCl₆.6H₂O, aPt-ether complex, a Pt-olefin complex, PdCl₂(PPh₃)₂, PdCl₂(PhCN)₂, andRhCl₂(PPh₃)₃ (in the formulae, Ph represents a phenyl group) can beused. The catalyst can be one catalyst alone or a mixture of two or morecatalysts. The catalyst can be diluted with a solvent of alcohols,aromatic compounds, hydrocarbons, ketones, a basic solvent, or the likeas necessary and used. In particular, a complex of1,1,3,3-tetramethyl-1,3-divinyldisiloxane and neutralized sodiumbicarbonate of chloroplatinic acid (Karstedt's catalyst) is the mostsuitable as an addition reaction catalyst.

It is sufficient for the amount of the catalyst to be a catalyticamount. A catalytic amount refers to an amount sufficient for making theaddition reaction progress. The amount of the catalyst is 0.02 parts bymass or less in terms of the main metal of the metal catalyst,preferably 0.0001 to 0.02 parts by mass, particularly preferably 0.0003to 0.005 parts by mass relative to 100 parts by mass ofhydrogensiloxane. The catalyst can be added from the beginning of thereaction or can be added during the reaction over several times. In theinventive production method, the reaction can be sufficiently progressedeven with a low amount of catalyst. However, if the amount of thecatalyst is too low, reaction rate becomes slow, and therefore, theamount is preferably the above-described lower limit or more. Meanwhile,too large an amount of the catalyst is uneconomical and unfavorable, anddoes not particularly improve the reaction rate.

The amount of the compound represented by the general formula (III) isnot particularly limited, and normally, the total number of alkenylgroups the compound represented by the general formula (III) has is 0.1to 10, preferably 0.5 to 2 relative to one hydrosilyl group of thehydrogensiloxane.

The addition reaction may be without a solvent or an organic solvent maybe used if necessary. As the organic solvent, an aromatic hydrocarbonsolvent such as toluene, xylene, and benzene; an aliphatic hydrocarbonsolvent such as hexane, cyclohexane, methylcyclohexane, andethylcyclohexane; a chlorinated solvent such as chloroform,dichloromethane, and carbon tetrachloride; an ether solvent such astetrahydrofuran (THF) and diethyl ether; a ketone solvent such asacetone and methyl ethyl ketone; dimethylformamide (DMF), andacetonitrile, etc. can be used, for example. In particular, an aromatichydrocarbon such as toluene is the most suitable.

The addition reaction temperature is 20 to 250° C., preferably 40 to180° C., particularly preferably 80 to 120° C. The reaction time iswithin 20 hours, preferably within 12 hours, particularly preferablywithin 8 hours.

The inventive polymeric polymerization initiator can produce a(meth)acrylic-grafted silicone by group transfer polymerization. A(meth)acrylic-grafted silicone produced by the inventive polymericpolymerization initiator has few by-product polymers unlike in a casewhere the (meth)acrylic-grafted silicone is synthesized by radicalpolymerization, and is therefore useful for cosmetics, fiber treatmentagents, water repellents, oil repellents, release agents, and coatingadditives, for example.

EXAMPLE

Hereinafter, the present invention will be described in more detail withreference to Examples and Comparative Examples, but the presentinvention is not limited to the following Examples. In the followingdescription, ¹H NMR analysis was performed using ECX-500 II(manufactured by JEOL Ltd.) and using deuterated chloroform as ameasuring solvent.

Note that the number-average molecular weight referred to in the presentinvention refers to a number-average molecular weight measured by GPCunder the following conditions using polystyrene as a standardsubstance.

[Measurement Conditions]

Developing solvent: tetrahydrofuran (THF)

Flow amount: 0.6 mL/min

Detector: Differential refractive index detector (RI)

Column: TSK Guard column SuperH-L

TSKgel SuperH4000 (6.0 mm I.D.×15 cm×1)

TSKgel SuperH3000 (6.0 mm I.D.×15 cm×1)

TSKgel SuperH2000 (6.0 mm I.D.×15 cm×2)

(each available from Tosoh Corporation)

Column temperature: 40° C.

Sample injection amount: 50 μL (THF solution with a concentration of 0.5mass %)

In addition, M^(Me), M^(H), D^(Me), D^(Ph), D^(H), T^(Me), and Qrepresent siloxane units, and each siloxane unit represents thefollowing structure.

M^(Me)=Me₃SiO_(1/2)

M^(H)=Me₂HSiO_(1/2)

D^(Me)=Me₂SiO_(2/2)

D^(Ph)=Ph₂SiO_(2/2)

D^(H)=MeHSiO_(2/2)

T^(Me)=MeSiO_(3/2)

Q=SiO_(4/2)

Here, Me represents a methyl group and Ph represents a phenyl group.

Example 1

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 7,780 g/mol) whose average composition was representedby M^(Me) ₂D^(Me) ₁₀₃D^(H) ₃₀ and 85.1 parts by mass of the compoundrepresented by the following formula (1), and were dissolved in 100parts by mass of toluene. The temperature of the solution was raised to100° C. using an oil bath, and 0.0333 parts by mass of a solution of aneutralized sodium bicarbonate of chloroplatinic acid-vinyl siloxanecomplex in toluene (platinum content: 0.5 wt %) was added dropwise.After adding dropwise, the solution was stirred for 6 hours whilekeeping the temperature of the solution at 100° C. Subsequently, thesolvent was removed at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 16,850 g/mol). FIG. 1 is a generalview of a ¹H NMR chart after the reaction between a hydrogensiloxane anda compound represented by the formula (1) in Example 1. The obtainedproduct was analyzed by ¹H NMR, and it was confirmed that the peakattributable to hydrosilyl groups had disappeared, and that there was apeak attributable to a ketene silyl acetal structure near a ¹H chemicalshift of 0.2 ppm, 0.5 ppm, 1.4 to 1.6 ppm, and 3.7 ppm.

Example 2

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 6,490 g/mol) whose average composition was representedby M^(Me) ₂D^(Me) ₁₂₃D^(H) ₁₀ and 28.4 parts by mass of the compoundrepresented by the formula (1), and were dissolved in 100 parts by massof toluene. The temperature of the solution was raised to 100° C. usingan oil bath, and 0.0333 parts by mass of a solution of a neutralizedsodium bicarbonate of chloroplatinic acid-vinyl siloxane complex intoluene (platinum content: 0.5 wt %) was added dropwise. After addingdropwise, the solution was stirred for 6 hours while keeping thetemperature of the solution at 100° C. Subsequently, the solvent wasremoved at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 13,110 g/mol). The obtained productwas analyzed by ¹H NMR, and it was confirmed that the peak attributableto hydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

Example 3

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 7,740 g/mol) whose average composition was representedby M^(Me) ₂D^(Me) ₁₁₃D^(H) ₂₀ and 55.6 parts by mass of the compoundrepresented by the formula (1), and were dissolved in 100 parts by massof toluene. The temperature of the solution was raised to 100° C. usingan oil bath, and 0.0333 parts by mass of a solution of a neutralizedsodium bicarbonate of chloroplatinic acid-vinyl siloxane complex intoluene (platinum content: 0.5 wt %) was added dropwise. After addingdropwise, the solution was stirred for 6 hours while keeping thetemperature of the solution at 100° C. Subsequently, the solvent wasremoved at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 14,960 g/mol). The obtained productwas analyzed by ¹H NMR, and it was confirmed that the peak attributableto hydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

Example 4

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 1,080 g/mol) whose average composition was representedby M^(Me) ₂D^(Me) ₁₀D^(H) ₅ and 120 parts by mass of the compoundrepresented by the formula (1), and were dissolved in 100 parts by massof toluene. The temperature of the solution was raised to 100° C. usingan oil bath, and 0.0333 parts by mass of a solution of a neutralizedsodium bicarbonate of chloroplatinic acid-vinyl siloxane complex intoluene (platinum content: 0.5 wt %) was added dropwise. After addingdropwise, the solution was stirred for 6 hours while keeping thetemperature of the solution at 100° C. Subsequently, the solvent wasremoved at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 2,850 g/mol). The obtained product wasanalyzed by ¹H NMR, and it was confirmed that the peak attributable tohydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

Example 5

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 2,950 g/mol) whose average composition was representedby M^(H) ₂D^(Me) ₄₀ and 16.9 parts by mass of the compound representedby the formula (1), and were dissolved in 100 parts by mass of toluene.The temperature of the solution was raised to 100° C. using an oil bath,and 0.0333 parts by mass of a solution of a neutralized sodiumbicarbonate of chloroplatinic acid-vinyl siloxane complex in toluene(platinum content: 0.5 wt %) was added dropwise. After adding dropwise,the solution was stirred for 6 hours while keeping the temperature ofthe solution at 100° C. Subsequently, the solvent was removed at 120° C.and 10 mmHg to obtain the target compound (number-average molecularweight: 3,920 g/mol). The obtained product was analyzed by ¹H NMR, andit was confirmed that the peak attributable to hydrosilyl groups haddisappeared, and that there was a peak attributable to a ketene silylacetal structure.

Example 6

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 4,220 g/mol) whose average composition was representedby M^(Me) ₂D^(Ph) ₉D^(H) ₄₃ and 154 parts by mass of the compoundrepresented by the formula (1), and were dissolved in 100 parts by massof toluene. The temperature of the solution was raised to 100° C. usingan oil bath, and 0.0333 parts by mass of a solution of a neutralizedsodium bicarbonate of chloroplatinic acid-vinyl siloxane complex intoluene (platinum content: 0.5 wt %) was added dropwise. After addingdropwise, the solution was stirred for 6 hours while keeping thetemperature of the solution at 100° C. Subsequently, the solvent wasremoved at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 14,500 g/mol). The obtained productwas analyzed by ¹H NMR, and it was confirmed that the peak attributableto hydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

Example 7

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 9,850 g/mol) whose average composition was representedby M^(Me) ₆D^(Me) ₁₁₃D^(H) ₂₀T^(Me) ₄ and 28.4 parts by mass of thecompound represented by the formula (1), and were dissolved in 100 partsby mass of toluene. The temperature of the solution was raised to 100°C. using an oil bath, and 0.0333 parts by mass of a solution of aneutralized sodium bicarbonate of chloroplatinic acid-vinyl siloxanecomplex in toluene (platinum content: 0.5 wt %) was added dropwise.After adding dropwise, the solution was stirred for 6 hours whilekeeping the temperature of the solution at 100° C. Subsequently, thesolvent was removed at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 15,230 g/mol). The obtained productwas analyzed by ¹H NMR, and it was confirmed that the peak attributableto hydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

Example 8

In a three-necked flask equipped with a thermometer and a cooling pipewere charged 100 parts by mass of hydrogensiloxane (number-averagemolecular weight: 7,720 g/mol) whose average composition was representedby M^(Me) ₁₀₀M^(H) ₂₀Q₆₀ and 39.9 parts by mass of the compoundrepresented by the formula (1), and were dissolved in 100 parts by massof toluene. The temperature of the solution was raised to 100° C. usingan oil bath, and 0.0333 parts by mass of a solution of a neutralizedsodium bicarbonate of chloroplatinic acid-vinyl siloxane complex intoluene (platinum content: 0.5 wt %) was added dropwise. After addingdropwise, the solution was stirred for 6 hours while keeping thetemperature of the solution at 100° C. Subsequently, the solvent wasremoved at 120° C. and 10 mmHg to obtain the target compound(number-average molecular weight: 10,210 g/mol). The obtained productwas analyzed by ¹H NMR, and it was confirmed that the peak attributableto hydrosilyl groups had disappeared, and that there was a peakattributable to a ketene silyl acetal structure.

As described above, it was confirmed that the inventive polymericpolymerization initiator was obtained.

It should be noted that the present invention is not limited to theabove-described embodiments. The embodiments are just examples, and anyexamples that have substantially the same feature and demonstrate thesame functions and effects as those in the technical concept disclosedin claims of the present invention are included in the technical scopeof the present invention.

The invention claimed is:
 1. A polymeric polymerization initiatorrepresented by the following general formula (I):M¹ _(a)M² _(b)D¹ _(c)D² _(d)T¹ _(e)T² _(f)Q_(g)  (I) M¹=R¹ ₃SiO_(1/2)M²=R¹ ₂R²SiO_(1/2) D¹=R¹ ₂SiO_(2/2) D²=R¹R²SiO_(2/2) T¹=R¹SiO_(3/2)T²=R²SiO_(3/2) Q=SiO_(4/2) wherein in the general formula (I), R¹ eachindependently represents a hydrogen atom, a substituted or unsubstitutedalkyl group having 1 to 10 carbon atoms, or a substituted orunsubstituted aryl group having 6 to 22 carbon atoms; R² represents agroup having a ketene silyl acetal structure represented by thefollowing general formula (II):

wherein in the general formula (II), A represents a single bond or adivalent organic group, R³ each independently represents a hydrogen atomor a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, and R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms, “a”, “c”, “d”,“e”, “f”, and “g” represent 0 or a positive integer and “b” represents 0where b+d+f≥1; the polymerization initiator represented by the generalformula (I) has a number-average molecular weight of 2,000 to 1,000,000g/mol; and an order of bonding of siloxane units represented by M¹, D¹,M², D², T¹, T², and Q is optionally determined.
 2. A method forproducing the polymeric polymerization initiator according to claim 1,the method comprising: adding a compound represented by the followinggeneral formula (III) to a hydrogensiloxane represented by the followinggeneral formula (IV) by a hydrosilylation reaction,

wherein in the general formula (III), A represents a single bond or adivalent organic group, R³ each independently represents a hydrogen atomor a substituted or unsubstituted alkyl group having 1 to 4 carbonatoms, and R⁴ each independently represents a substituted orunsubstituted alkyl group having 1 to 4 carbon atoms,M³ _(h)D³ _(i)T³ _(j)Q_(k)  (IV) M³=R⁵ ₃SiO_(1/2) D³=R⁵ ₂SiO_(2/2)T³=R⁵SiO_(3/2) Q=SiO_(4/2) wherein in the general formula (IV), R⁵ eachindependently represents a hydrogen atom, a substituted or unsubstitutedalkyl group having 1 to 10 carbon atoms, or a substituted orunsubstituted aryl group having 6 to 22 carbon atoms, and at least oneis a hydrogen atom; and “h”, “i”, “j”, and “k” represent 0 or a positiveinteger where h+i+j≥1; the hydrogensiloxane represented by the generalformula (IV) has a number-average molecular weight of 500 to 900,000g/mol; and an order of bonding of siloxane units represented by M³, D³,T³, and Q is optionally determined.